The present invention pertains to a cover feeding device for a book binding machine.
In the personalization of brochures produced on adhesive binders, personal data such as, for example, an address is printed on the covers shortly before they are combined with the book blocks.
The arrangement of the printing unit underneath the cover conveyor makes it possible to print the outside of the covers, for example, with an individual barcode for tracking personally compiled printed products until the production process is completed. The printed barcodes can be read at the entry of downstream processing devices so as to individually process the products, e.g., to insert additional personal contents into the printed product. The detection of the barcode at the end of the production process makes it possible to ensure that the respective personal printed product was actually produced.
The printing units used for this purpose frequently consist of digitally controlled inkjet printing heads in which the ink or printing color is transferred onto the cover in the form of extremely small droplets. However, a reliable printing process and a flawless performance of these printing heads cannot be ensured if the printing process is carried out from the bottom, namely because the printing heads are soiled by falling paper dust. Another problem is the ink receptivity of the usually finished cover surface. Back-dropping printing colors cause the print quality to deteriorate. In addition, the covers cannot be guided again within the printed region until the applied printing color has dried. The range of cover formats, as well as the positioning of the printed information, is significantly restricted if the printing process is carried out from the bottom and the printing head is positioned between the conveying means of the cover conveyor.